How do dolphins sleep?

The question of how dolphins sleep, deserves specialattention. The fact is that dolphins belong to the class of mammals, and all representatives of this class must sleep a certain part of the day. And it is assumed that during deep sleep the animal stays mostly in a state of immobility and loses control over its body. But such a dream is simply impossible for a dolphin. Dolphins must constantly rise to the surface to make their next breath of air.

Observations of these animals showed that dolphins never stay in complete immobility, they constantly rise to the surface from time to time. So are they sleeping at all?

Of course, the dolphins are asleep. But unlike other mammals, including humans, in dolphins during sleep, not both hemispheres of the brain are switched off, but only one - the second at this moment is awake, after which they change. Active - falls asleep, and the one that has already "slept" - carries its guard. It is this dream that provides animal safety and body control so that during a deep sleep the dolphin can continue to breathe in the required mode.